U.S. patent application number 12/275755 was filed with the patent office on 2010-05-27 for multi-layer acoustical plaster system.
Invention is credited to Lee K. Yeung.
Application Number | 20100129643 12/275755 |
Document ID | / |
Family ID | 42196572 |
Filed Date | 2010-05-27 |
United States Patent
Application |
20100129643 |
Kind Code |
A1 |
Yeung; Lee K. |
May 27, 2010 |
MULTI-LAYER ACOUSTICAL PLASTER SYSTEM
Abstract
An acoustical plaster system features a base layer mixture and a
finish layer mixture. The base layer mixture includes a first
binder, a first thickener and a plurality of first particles, with
the first particles being porous, lightweight, non-close packing
particles having a first mean diameter. The finish layer mixture
includes a powder latex binder, a second thickener and a plurality
of second particles, with the second particles being porous,
lightweight particles having a second diameter. The first mean
diameter is larger than said second mean diameter.
Inventors: |
Yeung; Lee K.; (Vernon
Hills, IL) |
Correspondence
Address: |
GREER, BURNS & CRAIN, LTD.
300 SOUTH WACKER DRIVE, SUITE 2500
CHICAGO
IL
60603
US
|
Family ID: |
42196572 |
Appl. No.: |
12/275755 |
Filed: |
November 21, 2008 |
Current U.S.
Class: |
428/327 ;
427/356; 427/403 |
Current CPC
Class: |
C04B 26/045 20130101;
E04B 1/82 20130101; E04B 1/8209 20130101; G10K 11/168 20130101;
C04B 26/02 20130101; C04B 26/285 20130101; E04B 2001/8263 20130101;
B32B 2307/102 20130101; C04B 28/02 20130101; E04B 2001/8461
20130101; G10K 11/165 20130101; C04B 2111/00612 20130101; G10K
11/162 20130101; Y02W 30/96 20150501; Y10T 428/254 20150115; C04B
2111/00568 20130101; C04B 2111/28 20130101; Y02W 30/91 20150501;
Y02W 30/97 20150501; C04B 2111/52 20130101; C04B 2111/1006
20130101; C04B 28/145 20130101; B32B 13/04 20130101; C04B 28/02
20130101; C04B 14/02 20130101; C04B 14/104 20130101; C04B 14/185
20130101; C04B 14/24 20130101; C04B 14/42 20130101; C04B 14/46
20130101; C04B 16/08 20130101; C04B 18/22 20130101; C04B 18/24
20130101; C04B 20/008 20130101; C04B 24/2611 20130101; C04B 24/383
20130101; C04B 38/085 20130101; C04B 40/0608 20130101; C04B 26/02
20130101; C04B 7/02 20130101; C04B 14/02 20130101; C04B 14/104
20130101; C04B 14/185 20130101; C04B 14/24 20130101; C04B 14/42
20130101; C04B 14/46 20130101; C04B 16/08 20130101; C04B 18/22
20130101; C04B 18/24 20130101; C04B 20/008 20130101; C04B 24/2611
20130101; C04B 24/383 20130101; C04B 38/085 20130101; C04B 40/0608
20130101; C04B 26/285 20130101; C04B 11/00 20130101; C04B 14/02
20130101; C04B 14/104 20130101; C04B 14/185 20130101; C04B 14/24
20130101; C04B 14/42 20130101; C04B 14/46 20130101; C04B 16/08
20130101; C04B 18/22 20130101; C04B 18/24 20130101; C04B 20/0032
20130101; C04B 20/008 20130101; C04B 24/2611 20130101; C04B 40/0608
20130101; C04B 2103/44 20130101; C04B 26/02 20130101; C04B 14/02
20130101; C04B 14/104 20130101; C04B 14/185 20130101; C04B 14/24
20130101; C04B 16/08 20130101; C04B 18/22 20130101; C04B 20/0032
20130101; C04B 20/008 20130101; C04B 24/2611 20130101; C04B 24/383
20130101; C04B 40/0608 20130101; C04B 2103/22 20130101; C04B 26/285
20130101; C04B 14/02 20130101; C04B 14/104 20130101; C04B 14/185
20130101; C04B 14/24 20130101; C04B 16/08 20130101; C04B 18/22
20130101; C04B 20/008 20130101; C04B 24/2611 20130101; C04B 24/383
20130101; C04B 38/085 20130101; C04B 40/0608 20130101; C04B 2103/22
20130101; C04B 26/045 20130101; C04B 14/18 20130101; C04B 24/383
20130101; C04B 28/145 20130101; C04B 14/18 20130101; C04B 24/2611
20130101; C04B 24/383 20130101; C04B 26/045 20130101; C04B 11/00
20130101; C04B 14/18 20130101; C04B 24/383 20130101 |
Class at
Publication: |
428/327 ;
427/356; 427/403 |
International
Class: |
B32B 5/16 20060101
B32B005/16; B05D 3/12 20060101 B05D003/12; B05D 1/36 20060101
B05D001/36 |
Claims
1. An acoustical plaster system to be applied to a substrate,
comprising: a base layer mixture that adheres to the substrate,
comprising a first binder, a first thickener and a plurality of
first particles, said first particles being porous, lightweight,
non-close packing particles having a first mean diameter; and a
finish layer mixture that adheres to said base layer mixture,
comprising a powder latex binder, a second thickener and a
plurality of second particles, said second particles being porous,
lightweight particles having a second diameter, wherein said first
mean diameter is larger than said second mean diameter.
2. The system of claim 1 wherein said first mean diameter is from
about 1000 microns to about 5000 microns.
3. The system of claim 1 wherein said second mean diameter is from
about 100 microns to about 500 microns.
4. The system of claim 3 wherein said first diameter is from about
1000 microns to about 5000 microns.
5. The system of claim 1 wherein one of said first particle and
said second particle comprises one of the group consisting of
expanded perlite, coated expanded perlite, glass microspheres,
resin microspheres, blown glass beads, gas-filled resin spheres,
polystyrene particles, hollow or porous ceramic beads,
polybutabiene particles, rubber particles and combinations
thereof.
6. The system of claim 1 wherein said base layer further comprises
acoustically absorbent fibers.
7. The system of claim 6 wherein said acoustically absorbent fibers
comprise at least one of the group consisting of mineral wool,
cotton, fiberglass, wood pulp and combinations thereof.
8. The system of claim 1 wherein said finish layer mixture is free
of starch.
9. The system of claim 1 wherein said finish layer mixture further
comprises a hydraulic component.
10. The system of claim 9 wherein said hydraulic component
comprises calcined gypsum.
11. The system of claim 9 wherein said finish layer mixture further
comprises water and a set retarder.
12. The system of claim 1 wherein each of said base layer mixture
and said finish layer mixture further comprises water.
13. The system of claim 1 further comprising a cushion layer that
adheres to the substrate and to which said base layer adheres.
14. The system of claim 13, wherein said cushion layer is selected
from the group consisting of a mastic, a thick adhesive, a
viscoelastic and a setting type cementations material, said cushion
layer having a viscosity of between 90,000 to 210,000 cps.
15. A method of preparing an acoustical plaster system comprising:
applying a base layer mixture to a substrate, said base layer
mixture comprising a binder, a thickener, water and a plurality of
first particles, said first particles being porous, lightweight,
non-close packing particles having a first mean diameter; allowing
said base layer mixture to harden to form a base layer; applying a
finish layer mixture to said base layer, said finish layer mixture
comprising a powder latex binder, a thickener, water and a
plurality of second particles, said second particles being porous,
lightweight particles having a second diameter, wherein said first
mean diameter is larger than said second mean diameter; and
allowing said finish layer mixture to harden to form a finish
layer.
16. The method of claim 15 wherein said substrate is panel
free.
17. The method of claim 15 wherein said second allowing step
comprises allowing said finish layer mixture to set.
18. The method of claim 15 wherein said second applying step
further comprises floating or troweling the finish layer.
19. The method of claim 15 further comprising spreading a cushion
layer onto the substrate prior to said first applying step.
Description
BACKGROUND
[0001] Trends to reduce noise pollution and provide quiet interior
spaces encourage the use of sound reducing materials, creating a
growing market for acoustical building materials. However, there is
also a desire for an aesthetically pleasing finish, since at least
one surface of the sound reducing material is visible from
inhabited areas.
[0002] Traditional plaster has a smooth monolithic appearance that
is considered to be a model surface. It accepts a variety of
decorative finishes, such as paint, wallpaper, and the new faux
finishes. However, the plaster also reflects sound, thereby
increasing noise pollution. Some sound frequencies are also
distorted, making the reflected sounds even less desirable.
[0003] Conventional acoustical panels are well-suited for absorbing
sounds. The surface of the panel is treated to provide openings
into which sounds penetrate. For example, the panel may be needled,
that is, it is punctured with rows of needles that create pores in
the panel surface. When combined with a porous panel structure, the
sounds enter the needle voids and pass into the panel pores. As the
sounds reflect off the walls of the voids or pores, a portion of
the sound is absorbed. This results in little or no sound exiting
the panel. However, the aesthetics of the panels are not widely
accepted and consumers are looking for an acoustical panel without
visible holes or fissures.
[0004] There are other acoustical systems commercially available
that deliver both an aesthetically pleasing finish and sound
attenuation. However, the systems require fixing of a specialty
fiberglass mat to the substrate with an adhesive, treatment of the
joints and application of a finish-coat plaster by hand. Thus,
these systems have several disadvantages. The specialty fiberglass
panel must be purchased and transported to the job site without
damage. A large number of specialty supplies are needed, including
the panel, adhesive and at least two types of acoustical plaster.
At least four time-consuming steps are needed for installation of
the panel, such as preparing the panel, adhering the panel,
treating the joints and applying the plaster.
[0005] Thus, it would be advantageous to design a system for
finishing a substrate that provides both improved sound absorbency
and an aesthetically pleasing surface.
SUMMARY OF THE INVENTION
[0006] One or more advantages of the present invention will be
clear to one skilled in the art. Specifically, the present
acoustical plaster system features a base layer mixture and a
finish layer mixture. The base layer mixture includes a first
binder, a first thickener and a plurality of first particles, with
the first particles being porous, lightweight, non-close packing
particles having a first mean diameter. The finish layer mixture
includes a latex binder, a second thickener and a plurality of
second particles, with the second particles being porous,
lightweight particles having a second diameter. The first mean
diameter is larger than said second mean diameter.
[0007] This plaster system has several advantages over the prior
art. There is no need to purchase, transport and install a
fiberglass panel over an existing substrate. Using the present
system, no panel is necessary at all. If a panel is used,
conventional, low-cost sound absorbing panels, such as a mineral
wool fiber panels, are suitable.
[0008] Use of the present system reduces the number and amount of
supplies that must be transported to the job site. Only two
packages, one of the base layer mixture and one of the finishing
layer mixture, need be taken to the building area. At least the
adhesive and panel can be omitted from the list of supplies that
are needed. Optionally, the materials can be premixed with water at
the production plant, further reducing jobsite mixing preparations
allowing the applicator to use the product directly out of the
packaging without the need to bring water onto the jobsite to mix
the product.
[0009] Additionally, the present acoustical plaster system requires
fewer steps to install it. There is no panel to install and no
joints to finish. Installation includes applying the base layer
mixture, then applying the finish layer mixture when the base layer
has hardened. The hardened acoustical plaster system has a
plaster-like finish. Sound passes through the acoustically
transparent finish layer, then is absorbed into the base layer.
Little or no sound is reflected back into the room.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a photograph of a base layer mixture applied to a
cushion layer on a substrate;
[0011] FIG. 2 is a photograph of the plaster system showing a
finish layer mixture applied to a base layer mixture on a cushion
layer; and
[0012] FIG. 3 is a photograph of a cross section of the plaster
system of FIG. 2 showing the relative thicknesses of the
layers.
DETAILED DESCRIPTION OF THE INVENTION
[0013] A plaster system includes a base layer mixture and a finish
layer mixture. It is contemplated that the acoustical plaster
system could be formulated with additional layers to optimize the
acoustics for specific applications.
[0014] The base layer mixture is applied to a substrate. Although
the base layer is optionally applied to a panel, the base layer is
advantageously applied where the substrate includes no underlying
panel. Examples of suitable substrates include wood, metal, cast
concrete, brick, wood or cellulosic particle composite boards,
cementitious boards, or paper-faced mineral panels.
[0015] The base layer is a sound absorbent layer. It includes a
system of interconnecting pores that extend throughout the
thickness of the base layer. Sounds are partially absorbed by the
base layer and partially reflected. The system of pores makes it
likely that a sound entering a pore is reflected within the pore
system until it is fully absorbed. This ensures that few sounds are
either reflected back into the room from which they came or
transmitted through to adjoining rooms.
[0016] Increasing the thickness of the base layer increases the
sound absorbency. A thicker base layer effectively increases the
torturous pathway available to dissipate a soundwave which enters
the material. Thus, the thickness of the base layer can be
selected, at least in part, by the desired degree of acoustical
absorbency. The base layer is at least 0.5 inch (1.3 cm) in
thickness in some embodiments. In some preferred embodiments, the
base layer thickness is about from 1 inch (2.5 cm) to about 2
inches (5 cm). It should be noted that to obtain thicker base
layers may require multiple applications of the base layer
material.
[0017] A primary component of the base layer mixture is a plurality
of first particles. The first particles are porous, lightweight,
non-close packing particles. Porous is defined as a material with a
large amount of interior void-space, typically from 8 to 45%.
Lightweight means a material having a density less than 0.3
g/cm.sup.3. Non-close packing particles are those that leave spaces
between at least some particle faces to create inter-particle
pores. Preferably, a system of interconnecting pores will be
created for sound management. Examples of first particles include
expanded perlite, coated expanded perlite, glass microspheres,
resin microspheres, blown glass beads, gas-filled resin spheres,
polystyrene particles, gas-filled inorganic spheres, hollow or
porous inorganic beads, polybutadiene particles, rubber particles,
elastomeric particles and combinations thereof. At least a portion
of the first particles are preferably inorganic particles to
maintain fire-resistance in the base layer. If organic particles
are used, appropriate flame resistant additives are preferably
incorporated into the formulation.
[0018] The first particles are relatively large. Preferably, they
have a first mean diameter of at least about 1000 microns. In some
embodiments, at least 85% of the first particles by volume have a
first mean diameter of about 1000 microns to about 5000 microns.
The amounts of the first particles range from about 3% to about 80%
based on the weight of the dry base layer mixture and depending on
if there is a hydraulic component.
[0019] Another component of the base layer mixture is a first
binder. Any typical adhesive binder is useful in the base layer
mixture. Starch and synthetic polymer binders, such as polyvinyl
alcohol and boric acid, homo and co polymers of polyvinyl acrylate,
polyvinyl acetate and polyurethane emulsion latexes are examples of
useful binders. Liquid emulsions are used if a ready-mixed base
layer mixture is desirable. Alternatively, spray-dried powders of
the corresponding emulsions can be used if a dry-mix formulation is
desired. The first binder is used in amounts of from about 1 to
about 15% based on the total weight of the dry base layer mixture
components or from about 2 to 20% based on the total weight of a
ready-mixed wet formulation.
[0020] The base layer mixture optionally includes a hydraulic
component, such as calcined gypsum. Many forms of calcined gypsum
are useful, including alpha and beta calcined forms. Either natural
or synthetic gypsums can be used. Other suitable hydraulic
components include Portland cement, variations such as Portland
flyash cement and masonary cements. Some preferred embodiments of
the base layer mixture are free of hydraulic components. A
preferred hydraulic component is beta calcium sulphate hemihydrate.
When present, about 10 to about 40% of the weight of the dry base
layer mixture is the hydraulic component. Optionally, set
accelerators familiar to those skilled in the art can be used,
examples include calcium sulphate hemihydrate in Portland cement
formulations and alum in calcium sulfate hemihydrate plaster
formulations.
[0021] At least one thickener is used in the base layer mixture to
increase the viscosity of the aqueous base layer mixture
sufficiently that it does not run or drip from the substrate prior
to hardening, makes the material easier to apply and can act as an
air entrainment agent to further reduce the weight of the wet
material and produce more pores per volume in the dried material.
Cellulosic thickeners are preferred thickeners. Examples of
suitable thickeners include modified cellulosics such as the
BERMOCOLL.RTM. products (Akzo Nobel, Stenungsund, Sweden) and
METHOCELO and CELLOSIZE.RTM. products (Dow Wolff Cellulosics,
USA/Germany). They are optionally used in amounts of about 2 to
about 8% based on the weight of the dry base layer mixture.
Optionally, inorganic extenders such clays as bentonite or
attapulgite or ultrafine ground calcium carbonate can be used to
further modify the rheology to facilitate application.
[0022] It is contemplated that the first thickener be either a
single thickener or a package of thickening components. Thickening
and foaming are often related. Many thickeners are foaming agents
that entrain air during mixing. A balance must be achieved between
the rheological properties of the base material and the amount of
foam produced. Although it is preferable to find a single thickener
that produces the optimum balance, one skilled in the art would
also know that a particular combination of thickness and foam is
also achievable by combining one or more thickeners with foaming
agents or defoaming agents.
[0023] Optionally, the base layer mixture includes acoustically
absorbent fibers. Such fibers are well-known for sound-absorption
and include, for example, mineral wool fibers, cotton fibers, fiber
glass, cellulosic fibers and combinations thereof. The fibers are
used in amounts of from about 1 to about 70% based on the weight of
the dry base layer mixture.
[0024] The finish layer mixture produces a finish layer that
hardens to a smooth monolithic surface. It is applied to the base
layer by any known means, including spraying and hand troweling.
The finish layer mixture generally includes a second binder, a
second thickener package and the second particles.
[0025] The second binder for the finish layer is preferably a
starch or synthetic polymer binders such as polyvinyl alcohol and
boric acid, homo and co polymers of polyvinyl acrylate, polyvinyl
acetate and polyurethane emulsion latexes. Alternatively,
spray-dried powders of the corresponding emulsions can be used if a
dry-mix formulation is desired. Liquid emulsions are used if a
ready-mixed base layer mixture is desirable. The powder latex is
used in amounts of about 1% to about 15% by weight of the dry
finish layer mixture. Since the pores of the finish layer are
smaller than those of the base layer, use of binders that clog the
pores may not be suitable when smaller pores are produced.
[0026] Also included in the finish layer mixture is a second
thickener. As with the first thickener, cellulosic thickeners are
preferred and inorganic extenders can optionally be used. The
second thickener is used in amounts of from about 8 to about 20% by
weight of the dry finish layer mixture. As discussed above with
respect to the first thickener, it is contemplated that the second
thickener be either a single thickener or a package of thickening
components. The second thickener can be the same or different from
the first thickener.
[0027] One component of the finish layer is a plurality of second
particles. The second particles are porous, lightweight particles
as these terms are defined above, but having a second mean diameter
that is smaller than the first mean diameter. In some preferred
embodiments, the second mean diameter is from about 100 microns to
about 500 microns. Use of smaller diameter particles allows the
finish to appear smoother than the base layer mixture while
maintaining an overall porous structures that allows soundwave to
pass through and be absorbed by the base layer. Depending on if
there is a hydraulic component, the amounts of the second particles
range from about 3% to about 80% based on the weight of the dry
base layer mixture.
[0028] The same types of particles that are suggested for use as
the first particles are also useful as the second particles.
However, the first mean particle diameter is larger than the second
mean particle diameter. Amounts of the second particle range from
about 50% to about 80% based on the weight of the dry finish layer
mixture.
[0029] As with the base layer mixture, optionally the finish layer
mixture includes a hydraulic component as described above. When
present, about 10 to about 40% of the weight of the dry finish
layer mixture is the hydraulic component.
[0030] As described above, the base layer mixture and the finish
layer mixture can be prepared as dry mixtures. They can each be
packaged separately for use at a job site where the water is added
just prior to use. It is also contemplated that a package of the
dry base layer mixture and a package of the finish layer mixture be
sold together as a kit for improving sound absorption of a
substrate. Preferably, the ratio of the base layer mixture to the
finish layer mixture is from about 1:0.1 to about 1:0.25.
[0031] The water to be added should be as pure as practical. If
hydraulic components are present, some aqueous impurities can
interact with the hydraulic components of either the base layer
mixture or finish layer mixture to produce unwanted results. For
example, salts present in the water can act as a set retarder or
set accelerator for the optional calcined gypsum, changing the
amount of time when the plaster is workable leading to difficulties
in application. Once applied, the material may set at different
rates and cause dryout or cracking issues. In some embodiments,
water is added to the base layer mixture in ratios of from about
2:1 to about 4:1 by weight. The ratio of water to the finish layer
mixture in other embodiments is from about 4:1 to about 6:1 by
weight.
[0032] Another option is the preparation of the base layer mixture
and/or the finish layer mixture in a form that is ready to use. It
will remain workable as long as the water does not evaporate. If a
hydraulic component is present in the formulation, the set
mechanism can be deactivated according to U.S. Pat. No. 6,805,741
B1 and U.S. Ser. No. 12/107,382, filed Apr. 22, 2008, hereby
incorporated by reference. Once the material is ready to use, a
suitable activator described in the prior art can be utilized.
[0033] When a ready-mixed formula is prepared, it is also
advantageous to add a preservative to prevent growth of microbes.
Without the addition of a biocide, microbes that are present in the
base layer mixture or the finish layer mixture from the water or
the air can flourish where there is moisture and organic particles
for food. Use of such a biocide is known to an artisan. Examples of
useful biocides include pyrithione salts, boric acid,
diiodotolusulfone and other known preservatives. The biocide is
normally used in amounts of less than 1% based on the wet
mixture.
[0034] The acoustical plaster system is prepared by a number of
methods. To prepare the dry base layer mixture, all of the desired
components described above, including the binder, the first
thickener, and the plurality of first particles, are acquired in a
dry form. After measuring each of the components to obtain
appropriate amounts, the components are dry blended until a
homogeneous mixture is achieved. If the base layer mixture is not
intended for immediate use, it is optionally packaged to keep it
dry. The dry finish layer mixture is prepared separate from the
base layer mixture but in a similar manner using the powder binder,
the second thickener, and the plurality of second particles.
[0035] If the base layer mixture and the finish layer mixture are
supplied as dry mixtures, water is added prior to application of
the layers. A first portion of water is first added to the base
layer mixture. A sufficient amount of water is added to the base
layer mixture so that it adheres to the substrate. The amount of
water used in the first portion of water may depend on the method
of application of the base layer mixture. If the base layer mixture
is sprayed onto the substrate, a thinner mixture may be
advantageous, requiring a larger amount of water. In some
embodiments, the first portion of water is used in amounts of from
about 30% to about 85% by weight of the final wet formulation.
[0036] The base layer mixture is applied to the substrate by any
suitable means. In some embodiments, the base layer mixture is
applied to the substrate by spraying or by using a trowel. If a
smooth, monolithic surface is desired, the surface of the base
layer is optionally smoothed with a trowel. Although it is
beneficial to smooth the base layer to approximately a constant
thickness, small surface imperfections can be ignored as they will
be covered by the finish layer. After application of the base layer
mixture, it is allowed to dry or harden until dry to the touch or
approximately 12 hours to form the base layer. The exact drying
time will be effected by ambient temperature and humidity as well
as the thickness of the material applied.
[0037] Preparation of the finish layer mixture for application to
the base layer proceeds similarly. After preparing or obtaining the
finish layer mixture, the second portion of water is added to make
a wet mixture. As with the base layer mixture, the amount of water
in the second portion of water may vary with the method of
application. In some embodiments, the second portion of water
ranges from about 30% to about 85% based on the final wet finish
layer mixture. If the finish layer mixture includes the optional
hydraulic component, it should be noted that the addition of water
to the dry finish layer mixture can initiate hydration reactions.
Sufficient time should be allowed between water addition and
application of the finish layer before it hardens.
[0038] As with the base layer mixture, the finish layer mixture is
applied using any suitable method, including spraying and
troweling. After application, the finish layer mixture is
optionally finished to produce the desired surface, such as a
smooth, monolithic surface. Floating and troweling are preferred
methods of finishing the finish layer mixture. After finishing the
finish layer mixture it is allowed to harden. The finish layer
mixture hardens at least partially by drying. If the optional
hydraulic component is present, hydration of the hydraulic
component also contributes to hardening of the finish layer
mixture. The surface of the final finish can be further smoothed by
sanding with conventional sanding tools used in joint compound wall
finishing procedures.
[0039] If either of the base layer or finish layer mixtures are
provided in a ready-mixed form containing water, the product is
used directly out of the container. Some settling may occur during
transport and storage prior to use, so the product is first stirred
and mixed to a homogeneous state. If a deactivated hydraulic
component is present, an activator is added along with the
stirring. The material is then applied in a manner similar to the
dry mixture form after the addition of water.
[0040] When the base layer mixture is applied to an inverted
surface that is hard, for example gypsum board panels, it may be
advantageous to spread a cushion layer on the substrate between it
and the base layer mixture. The cushion layer is a material that is
pliable as it is applied, although it optionally cures to form a
hard layer after application of the base layer mixture. Another
property of the cushion layer is that it provides additional
adhesion of the base layer mixture to the substrate. Examples of a
suitable cushion layer include a thick (preferably 90,000-210,000
cps) adhesive, such as a tile mastic adhesive, cementitious
mortars, curable viscoelastic material such as RTV rubber and
sealants. Examples of the cushion layer include USG DUROCK.TM. High
Performance Tile Mastic, USG DUROCK.TM. Latex Modified Fast-set
High Performance Mortar and USG brand Acoustical Sealant. The
cushion layer is particularly useful for base layer mixtures having
particles greater than 1 mm. Without the cushion layer, base layer
mixtures having large aggregates are difficult to apply to a hard,
inverted substrate. The base layer mixture is spread to the cushion
layer prior to hardening, curing or setting of the cushion
layer.
EXAMPLE 1
[0041] A ready-mixed base layer mixture formulation was prepared
using the components listed in Table 1. The dry components were
mixed in a V-shell dry blender for 5 minutes, then added to the
pre-mixed liquid components. All materials were then mixed in a
Hobart mixer equipped with paddles at about 60 RPM for 10-15
minutes.
TABLE-US-00001 TABLE I Component Function Amount Weight Percent
BERMOCOLL Thickener <4.4 g 0.8% 481FQ HP 42-296 Latex Emulsion
40 g 7.7% Galactosol Thickener 2 g 0.4% Perlite #5 inorganic 112 g
21.7% aggregate Water Solvent 360 g 69.4%
[0042] The base layer mixture was applied onto 10''.times.7'' inch
gypsum wallboard panels which had previously been coated with a
cushion layer using a 1/4'' notched trowel. When applied inverted
to the panels, the base layer mixture remained cohesive and did not
droop, sag or detach from the substrate.
EXAMPLE 2
[0043] A dry base layer mixture formulation is prepared using the
components listed in Table II. The dry components are mixed in a
V-shell dry mixer for 5 about minutes to form a dry powder
mixture.
TABLE-US-00002 TABLE II Component Function Amount Weight Percent
BERMOCOLL thickener 60 g 4.1% 481FQ VINNAPAS redispersible 300 g
20.3% 7037T latex powder Perlite #5 inorganic 1120 g 75.6%
aggregate
[0044] At the jobsite, 3800 g of water is added to the dry powder
mixture created above immediately prior to use. Stirring is
supplied by a common drill mixer equipped with a paddle.
EXAMPLE 3
[0045] A dry base layer mixture formulation is prepared using the
components listed in Table III. The dry components are mixed in a
V-shell dry mixer for 5 about minutes to form a dry powder
mixture.
TABLE-US-00003 TABLE III Component Function Amount Weight Percent
BERMOCOLL thickener 60 g 3.1% 481FQ VINNAPAS redispersible 300 g
15.7% 7037T latex powder Perlite #5 inorganic 1120 g 58.5%
aggregate Calcium Sulfate Cementious 435 g 22.7% hemihydrate
binder
[0046] At the jobsite, 4500 g of water is added to the dry powder
mixture created above immediately prior to use. Stirring is
supplied by a common drill mixer equipped with a paddle.
EXAMPLE 4
[0047] A ready-mix finish layer mixture formulation was prepared
using the components listed in Table IV. The dry components were
mixed in a V-shell dry mixer for 5 about minutes to form a dry
powder mixture, then added to the pre-mixed liquid components. All
materials were then mixed in a Hobart mixer equipped with paddles
at about 60 RPM for 10-15 minutes.
TABLE-US-00004 TABLE IV Component Function Amount Weight Percent
SuperGelB thickener 40.4 g 3.2% DCS thickener 6.8 g 0.5% STARPOL
163 thickener 2 g 0.1% AIRFLEX 3540 latex 54 g 4.3% emulsion Water
solvent 994.3 g 78.5% Perlite #9 inorganic 169.3 g 13.4%
aggregate
[0048] The finish layer mixture was applied to a cured basecoat
layer which previously had been applied onto a 10''.times.7'' inch
gypsum wallboard panel coated with a cushion layer using a 1/4''
notched trowel. The finish layer mixture was smooth and had
moderately good application feel.
EXAMPLE 5
[0049] A dry finish layer mixture formulation was prepared using
the components listed in Table V. The dry components were mixed in
a V-shell dry mixer for 5 about minutes to form a dry powder
mixture.
TABLE-US-00005 TABLE V Component Function Amount Weight Percent
SuperGelB thickener 28.4 g 13.1% DCS thickener 6.8 g 3.0% STARPOL
163 thickener 4 g 1.8% VINNAPAS redispersible 25.7 g 11.4% 7037T
latex powder Perlite #39 inorganic 160 g 71.1% aggregate
[0050] At the jobsite, 994.3 g of water was added to the dry powder
mixture created above immediately prior to use. Stirring was
supplied by a common drill mixer equipped with a paddle. When
applied to a substrate to evaluate the look, this finish layer
mixture was found to have moderate application feel but be slightly
runny. When dry, the coating was smooth.
EXAMPLE 6
[0051] A dry finish layer mixture formulation is prepared using the
components listed in Table VI. The dry components are mixed in a
V-shell dry mixer for 5 about minutes to form a dry powder
mixture.
TABLE-US-00006 TABLE VI Component Function Amount Weight Percent
SuperGelB thickener 300 g 14% DCS thickener 55 g 2.8% STARPOL 163
thickener 43 g 2.2% VINNAPAS redispersible 257 g 12.9% 7037T latex
powder Perlite #3-S inorganic 1021 g 51.2% aggregate Calcium
Sulfate cementious 320 g 16.0% hemihydrate binder
[0052] At the jobsite, 10 kg of water is added to the dry powder
mixture created above immediately prior to use. Stirring is
supplied by a common drill mixer equipped with a paddle.
EXAMPLE 7
[0053] A base layer mixture formulation was prepared using the
components of Table VII. The dry components are mixed in a V-shell
dry mixer for 5 about minutes to form a dry powder mixture. Water
was then added to the dry components to make a paste.
TABLE-US-00007 TABLE VII Component Function Amount Weight Percent
Water solvent 90 g 69.7% Bermocoll 481 thickener 1.1 g 0.9% FQ
Supercote Acrylic Latex 10 g 7.7% Emulsion Perlite #5 Inorganic 28
g 21.7% aggregate
[0054] Prior to installation of the prepared base layer mixture, a
cushion layer about 1/4 to about 1/2 inch in thickness (6-12 mm) of
USG DUROCK.TM. High Performance Tile Mastic was applied to a
substrate. While the cushion layer was still pliable, the base
layer mixture was applied to the surface of the cushion layer, as
shown in FIG. 1.
EXAMPLE 8
[0055] A finish layer mixture was prepared from the components of
Table VIII.
TABLE-US-00008 TABLE VIII Component Function Amount Weight Percent
Water solvent 1988.6 g 79.1% SuperGelB thickener 56.8 2.3% DCS
thickener 13.6 0.5% Starpol 163 thickener 8.2 g 0.3% HP 41-830
latex powder 108 g 4.3% Ryolex 39 Perlite aggregate 338.6 g
13.5%
[0056] After curing of the base layer mixture of Example 7, the
finish layer mixture was applied to the exposed surface of the base
layer mixture. FIG. 2 shows a top view of the finish layer, base
layer mixture and cushion layer, while a cross section of the
finish layer mixture, base layer mixture and cushion layer system
is shown in FIG. 3.
[0057] While a particular embodiment of the multi-layer acoustical
plaster system has been shown and described, it will be appreciated
by those skilled in the art that changes and modifications may be
made thereto without departing from the invention in its broader
aspects and as set forth in the following claims.
* * * * *